RESUMO
Arterial hypertension induces numerous alterations in the composition of cardiac tissue, which, in turn, result in structural remodeling of the myocardium. This remodeling is due to a range of pathologic mechanisms associated with mechanical, neurohormonal and cytokine processes that affect both cardiomyocyte and non-cardiomyocyte compartments of the myocardium. One of these processes involves disruption of the equilibrium between the synthesis and degradation of type-I and type-III collagen molecules. The result is excess accumulation of type-I and type-III collagen fibers in interstitial and perivascular spaces in the myocardium. The clinical significance of myocardial fibrosis lies in its contribution to the development of cardiac complications in hypertensive patients. This brief review focuses on the mechanisms of myocardial fibrosis and their clinical consequences. In addition, the techniques used for diagnosing myocardial fibrosis and the main therapeutic strategies for reducing fibrosis are also discussed.
Assuntos
Cardiomiopatias/diagnóstico , Colágenos Fibrilares/metabolismo , Insuficiência Cardíaca/etiologia , Hipertensão/complicações , Miocárdio/metabolismo , Miocárdio/patologia , Animais , Anti-Hipertensivos/uso terapêutico , Colágeno Tipo I/metabolismo , Colágeno Tipo III/metabolismo , Modelos Animais de Doenças , Fibrose Endomiocárdica/diagnóstico , Fibrose Endomiocárdica/etiologia , Fibrose/diagnóstico , Fibrose/patologia , Previsões , Humanos , Hipertensão/diagnóstico , Hipertensão/tratamento farmacológico , Hipertensão/metabolismo , Hipertensão/terapia , Miócitos Cardíacos/metabolismo , Guias de Prática Clínica como Assunto , Ratos , Ratos Endogâmicos WKYRESUMO
The aim of this study was to determine whether there are differences in echocardiographic findings or in the level of a biochemical marker (i.e. N-terminal probrain natriuretic peptide [NT-proBNP]) between controls and type-2 diabetic patients with or without ischemic heart disease. Echocardiography was used to assess left ventricular function and morphology. In addition, the plasma NT-proBNP concentration was measured. The prevalence of diastolic dysfunction was greater in diabetics without ischemic heart disease than in controls (88% vs. 74%, respectively; P< .001) and the NT-proBNP concentration was higher (350.6+/-197.8 vs. 281.7+/-190.4 fmol/mL; P< .001). Diabetics with ischemic heart disease had a higher NT-proBNP concentration than those without (720.4+/-278.1 vs. 350.6+/-197.8 fmol/mL, respectively; P< .001). An NT-proBNP concentration >490 fmol/mL had a sensitivity of 84% and a specificity of 75% for detecting ischemic heart disease in diabetics.